Single-bridge and double-bridge switching control method and system for double drive axles with different powers

Abstract

The invention relates to a single-double-axle switching control method and system for double drive axles with different powers. The method comprises the steps that a double-axle drive mode is initialized after starting; vehicle operation parameters and driver operation intention are obtained, and the driving mode is re-evaluated; determining a current road condition and / or a vehicle load according to the vehicle operation parameters, judging whether to switch to a single-axle driving mode or not at least based on the current road condition or the vehicle load, and determining a main driving axle in the single-axle driving mode; determining an accelerator pedal opening degree and / or a braking energy recovery gear according to the operation intention of the driver, and triggering to switch to a double-axle driving mode when the accelerator pedal opening degree and / or the braking energy recovery gear exceed respective preset thresholds; based on the driving mode needing to be switched, target driving torque and a torque adjusting strategy needed by the driving axle are determined; and in the switching process of the driving modes, the driving torque is dynamically adjusted based on the torque adjustment strategy, so that the driving torque is gradually converged to the target driving torque.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle drive control, and in particular to a single-bridge and double-bridge switching control method and system for dual-drive bridges with different powers. Background Art

[0002] With the continuous improvement of environmental protection requirements and the growing development of electric vehicle technology, pure electric tractors have been more and more widely used in logistics and transportation and other fields. In pure electric tractors, the dual-drive axle structure has greater driving force and carrying capacity, and can better adapt to various complex road conditions.

[0003] However, in actual use, different transportation tasks and road conditions have different driving requirements for vehicles. Sometimes only a single-bridge drive is needed to meet the requirements, while in some heavy loads or severe road conditions, a dual-bridge drive is required to provide sufficient power. However, the existing technology cannot efficiently switch between single-bridge and dual-bridge drive modes according to the vehicle's load, road conditions and driving requirements, resulting in the vehicle either having excess power and wasting energy, or insufficient power and affecting performance under certain working conditions. And due to the limitations of the drive system and control strategy, existing vehicles cannot ensure that the motor and transmission system always operate in the optimal efficiency area, making it difficult to effectively reduce energy consumption. Furthermore, in the case of dual-motor torque coupling, it is impossible to achieve precise control of the torque at each wheel end, which limits the vehicle's driving performance and driving stability under complex road conditions.

[0004] Therefore, how to realize the single-bridge and double-bridge switching control of a tractor equipped with drive axles of different power to achieve the best driving effect and energy utilization efficiency has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The invention discloses a single-bridge and double-bridge switching control method and system for dual-drive bridges with different powers, aiming to solve the technical problems existing in the prior art.

[0006] The present invention adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a single-bridge and double-bridge switching control method for dual-drive bridges of different powers, the method comprising:

[0008] Initialize the dual-bridge drive mode after starting;

[0009] Obtain vehicle operating parameters and driver operation intentions to re-evaluate the driving mode;

[0010] determining a current road condition and / or a vehicle load according to vehicle operating parameters, determining whether to switch to a single-axle drive mode based at least on the current road condition or the vehicle load, and determining a main driving axle in the single-axle drive mode;

[0011] Determine the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operating intention, and trigger switching to the dual-axle drive mode when they exceed their respective preset thresholds;

[0012] Determine the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched;

[0013] During the switching process of the driving mode, the driving torque is dynamically adjusted based on the torque adjustment strategy so that it gradually converges to the target driving torque.

[0014] In some embodiments, the step of initializing the dual-bridge driving mode after starting specifically includes:

[0015] Determine whether the vehicle is in the starting state;

[0016] When it is confirmed that the vehicle is in the starting state, two drive axles with different powers are activated at the same time, and the initial drive torque of the two drive axles is dynamically distributed;

[0017] The vehicle speed is monitored and when the vehicle speed reaches a preset speed threshold, a re-evaluation of the driving mode is triggered.

[0018] In some embodiments, the step of obtaining vehicle operating parameters and driver operation intention specifically includes:

[0019] Acquiring vehicle operating parameters, wherein the vehicle operating parameters include at least one of vehicle speed, acceleration, motor temperature, current gear position of the gearbox, motor allowable torque, motor allowable current, battery remaining power, battery allowable current, and load signal;

[0020] The driver's operation intention is obtained, where the driver's operation intention includes at least one of a driving mode selection, an accelerator pedal opening, a brake pedal opening, an RND gear request, and an energy recovery gear signal.

[0021] In some embodiments, the step of determining the current road condition or vehicle load according to the vehicle operating parameters specifically includes:

[0022] Obtaining the driving force and acceleration of the vehicle, or obtaining the braking force and deceleration of the vehicle;

[0023] Determining the current vehicle mass based on a relationship between driving force and acceleration, or based on a relationship between braking force and deceleration;

[0024] Compare the obtained vehicle mass with the preset unloaded mass and fully loaded mass;

[0025] Based on the comparison result, the vehicle load state is determined.

[0026] In some embodiments, the step of determining the current road condition or vehicle load according to the vehicle operating parameters specifically includes:

[0027] Determining a road slope angle based on vehicle operating parameters;

[0028] The calculated slope angle is compared with the preset flat ground threshold and ramp threshold, and the current road condition is determined based on the comparison result.

[0029] In some embodiments, the step of determining whether to switch to the single-bridge drive mode based at least on the current road condition or vehicle load, and determining the main drive axle in the single-bridge drive mode specifically includes:

[0030] Set the mass coefficient to map the vehicle mass range to the preset mass coefficient range;

[0031] When the mass coefficient is less than the first preset threshold, it is determined to switch to the single-bridge drive mode, and the low-power bridge is selected as the main drive bridge;

[0032] When the mass coefficient is greater than the second preset threshold and less than the third preset threshold, it is determined to switch to the single-bridge drive mode and select the high-power bridge as the main drive bridge;

[0033] When the quality coefficient is greater than or equal to the third preset threshold, the dual-bridge driving mode is maintained.

[0034] In some embodiments, the step of determining whether to switch to the single-bridge drive mode based at least on the current road condition or vehicle load, and determining the main driving axle in the single-bridge drive mode, further includes:

[0035] When it is determined that the current road condition is uphill and the slope angle is greater than the preset slope threshold, regardless of the mass coefficient, the dual-axle drive mode is maintained or switched to.

[0036] In some embodiments, the step of determining the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention and triggering switching to the dual-bridge drive mode when the respective preset thresholds are exceeded specifically includes:

[0037] Obtain current gearbox gear information and real-time accelerator pedal opening signal;

[0038] According to the current gear position, determine the corresponding maximum driving force boundary value;

[0039] Compare the real-time accelerator pedal opening signal with the maximum driving force boundary value corresponding to the current gear position;

[0040] When the accelerator pedal opening signal exceeds a preset percentage of the maximum driving force boundary value, switching to the dual-axle driving mode is triggered.

[0041] In some embodiments, the step of determining the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention and triggering switching to the dual-bridge drive mode when the respective preset thresholds are exceeded specifically includes:

[0042] Set multiple levels of braking energy recovery intensity, each level corresponds to different braking force;

[0043] Obtaining a brake energy recovery gear position signal selected by a driver;

[0044] comparing the selected braking energy recovery gear signal with a preset braking energy recovery intensity;

[0045] When the selected braking energy recovery gear signal is greater than or equal to the braking energy recovery intensity, it triggers switching to the dual-axle drive mode;

[0046] The vehicle speed is monitored and when the vehicle speed drops to a preset low-speed threshold, the system re-evaluates whether it is necessary to maintain the dual-axle drive mode.

[0047] In some embodiments, the method further includes the steps of fault diagnosis and processing:

[0048] Based on vehicle operating parameters, real-time monitoring of vehicle operating status;

[0049] When a fault is detected, the specific fault information is identified through the preset fault code;

[0050] Determine the type and severity of the fault based on the identified fault information;

[0051] Based on the fault type and severity, the corresponding single-bridge or double-bridge switching strategy is executed.

[0052] In some embodiments, the step of executing the corresponding single-bridge and double-bridge switching strategy based on the fault type and severity specifically includes:

[0053] When the motor controller, motor or gearbox of a single drive axle fails seriously and cannot be used, it will automatically switch to another drive axle as the drive;

[0054] When a torque limit fault is detected, the torque output of the faulty axle is limited and the torque distribution ratio of the other drive axle is increased;

[0055] When switching drive modes in the event of a fault, the drive torque is dynamically transferred based on the torque adjustment strategy;

[0056] The fault condition is continuously monitored and the drive mode is re-evaluated when the fault condition is resolved.

[0057] In a second aspect, an embodiment of the present invention provides a single-double bridge switching control system for dual-drive bridges of different powers, the system comprising:

[0058] Initial drive module, used to initialize the dual-bridge drive mode after starting;

[0059] An acquisition module, used to acquire vehicle operating parameters and driver operation intentions, and perform a re-evaluation of the driving mode;

[0060] A first evaluation module, configured to determine a current road condition and / or a vehicle load according to a vehicle operating parameter, determine whether to switch to a single-axle drive mode at least based on the current road condition or the vehicle load, and determine a main driving axle in the single-axle drive mode;

[0061] The second evaluation module is used to determine the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention, and trigger the switch to the dual-axle drive mode when the respective preset thresholds are exceeded;

[0062] A torque control module, used to determine the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched;

[0063] The driving mode switching module is used to dynamically adjust the driving torque based on the torque adjustment strategy during the switching process of the driving mode so that it gradually converges to the target driving torque.

[0064] One embodiment of the above invention has the following advantages or beneficial effects:

[0065] The embodiment of the present invention mainly provides a single-bridge and double-bridge switching control method and system for dual-drive bridges of different powers. The aforementioned control method intelligently switches between single-bridge and double-bridge drive modes, adjusts the drive mode in real time according to various factors such as vehicle load, road conditions, and driver operation, thereby reducing unnecessary energy consumption. Specifically, based on the control method, it is possible to switch to single-bridge drive under light load and flat road conditions, and further select a high-power bridge or a low-power bridge to reduce the energy consumption of the entire vehicle. Under high load conditions such as heavy load or uphill, it is possible to switch to the double-bridge drive mode in time to provide stronger driving force. During the drive mode switching process, a dynamic torque adjustment strategy is adopted to ensure a smooth transition and improve driving comfort.

[0066] Furthermore, the control method also introduces a fault diagnosis and processing mechanism. Through real-time monitoring and dynamic adjustment, it can automatically switch to another bridge drive when a single bridge fails, thereby improving the system's fault tolerance and reducing the impact of power system failures on vehicle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0068] Figure 1 A flow chart of a single-bridge and double-bridge switching control method for dual-drive bridges of different powers provided by an embodiment of the present invention;

[0069] Figure 2 A structural block diagram of a single-bridge and double-bridge switching control system for dual-drive bridges of different powers provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise. In the following embodiments, "drive axle" or "bridge" refers to "electric drive axle".

[0071] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0072] refer to Figure 1 In order to solve the deficiencies in the prior art, the present invention provides a single-double-bridge switching control method for dual-drive axles with different powers. The control method is preferably applicable to pure electric commercial vehicles, and the vehicles are equipped with two drive axles with different powers. In some embodiments, the pure electric commercial vehicle can select a 6×4 pure electric tractor, and the power of the two drive axles is not specifically limited here.

[0073] like Figure 1 In one embodiment of the present invention, the single-bridge and double-bridge switching control method of dual-drive bridges with different powers at least includes steps S110 to S160.

[0074] Step S110, initializing the dual-bridge driving mode after starting.

[0075] In one embodiment of the present invention, after the vehicle is powered on, it is determined whether the vehicle is in a starting state. When it is confirmed that the vehicle is in a starting state, two drive axles with different powers are activated at the same time, and the initial drive torque of the two drive axles is dynamically allocated; the vehicle speed is monitored, and when the vehicle speed reaches a preset speed threshold, a re-evaluation of the driving mode is triggered.

[0076] Specifically, after the vehicle is powered on, it can determine whether the vehicle is stationary based on the vehicle speed, or determine whether the forward gear has been engaged or the parking brake has been released by monitoring the driver's operation. When it is detected that the vehicle speed is not 0, or the forward gear has been engaged, or the parking brake has been released, it is determined that the vehicle is in the starting state. Once it is confirmed that the vehicle is in the starting state, the system simultaneously activates two drive axles of different powers to provide greater total driving force and vehicle traction to ensure that the vehicle can start smoothly, especially in high-load conditions such as load / full load or uphill. At the same time, it can also disperse the driving force more evenly to reduce the risk of a single drive axle being overloaded.

[0077] In one embodiment of the present invention, when two drive axles are activated at the same time, a conservative torque distribution strategy can be adopted in the initial stage to ensure smooth starting, for example, the high-power drive axle bears 60-70% of the driving torque, and the low-power drive axle bears 30-40% of the driving torque. During the entire starting process, the system continuously adjusts the torque distribution between the two drive axles to ensure the smoothness of the acceleration process. The torque distribution at this time can refer to any implementation method disclosed in the prior art, and this embodiment does not specifically limit it.

[0078] Specifically, a vehicle usually requires greater power at the start, but once it reaches a certain speed, the driving resistance and power requirements will change, and the full power output of the dual-axle drive may no longer be required. Therefore, a reassessment can be made based on the vehicle speed to promptly switch to a more energy-efficient drive mode, such as single-axle drive, thereby improving overall energy efficiency.

[0079] In one embodiment of the present invention, the real-time speed of the vehicle is continuously monitored during the initialization phase, and a preset initialization phase speed threshold is set. When the vehicle speed reaches or exceeds the preset speed threshold for the first time, the system triggers a re-evaluation process of the driving mode, and further evaluation and judgment can be made based on parameters such as the current road conditions and battery status. In this embodiment, the specific value of the initialization phase speed threshold is no longer limited, and those skilled in the art can freely select and adjust the threshold according to specific vehicle specifications or application scenarios.

[0080] In one embodiment of the present invention, vehicle operating parameters are obtained during the initialization phase. If it is determined that the vehicle is currently on a flat road, the vehicle is traveling at a relatively low speed, and the battery power is sufficient, it is determined that the single-bridge drive mode can meet the driving requirements. At this time, the dual-bridge drive mode is smoothly switched to the single-bridge drive mode, most of the power is allocated to one drive axle, and the other axle is controlled to enter a neutral state, so that the vehicle travels in the single-bridge drive mode to improve energy efficiency.

[0081] Step S120, obtaining vehicle operating parameters and driver operation intention, and performing a re-evaluation of the driving mode.

[0082] In one embodiment of the present invention, the vehicle operating parameters include at least one of vehicle speed, acceleration, motor temperature, current gear of the transmission, motor allowable torque, motor allowable current, battery remaining power, battery allowable current, and load signal.

[0083] Specifically, the above vehicle operating parameters are collected by corresponding sensors and transmitted to the vehicle control module VCU through the vehicle communication bus. Since the sensors for obtaining the above vehicle operating parameters are all known sensors, they will not be described one by one in this embodiment.

[0084] In one embodiment of the present invention, the driver's operation intention includes at least one of a driving mode selection, an accelerator pedal opening, a brake pedal opening, an RND gear request, and an energy recovery gear signal.

[0085] In one embodiment of the present invention, the driving mode is obtained through a mode selection switch or a touch screen interface operated by the driver, the accelerator pedal opening is measured by a position sensor installed on the accelerator pedal, the brake pedal opening is also obtained by measuring the travel of the brake pedal using a position sensor, the RND gear request is obtained through a position sensor of a shift lever or a shift button, and the energy recovery gear signal can be obtained by a corresponding position sensor or switch according to the actual structure of the vehicle.

[0086] Specifically, the above-mentioned driver's operation intention can be transmitted to the vehicle control module VCU through the body control module BCM or directly.

[0087] In this embodiment, the VCU serves as the central processing unit of the vehicle, receives and processes the above information, and performs a re-evaluation process of the driving mode in order to make the optimal driving mode decision.

[0088] Step S130, determining the current road condition and / or vehicle load according to the vehicle operating parameters, judging whether to switch to the single-bridge drive mode at least based on the current road condition or vehicle load, and determining the main driving axle in the single-bridge drive mode.

[0089] In one embodiment of the present invention, the current road condition and the vehicle load may be determined simultaneously or sequentially.

[0090] In one embodiment of the present invention, there are two ways to determine the vehicle load state. One way is to determine by a load signal fed back by an electronic braking system EBS, and the other way is for the VCU to perform autonomous calculations using a dynamics formula.

[0091] In one embodiment of the present invention, the main logical formula of the load signal fed back by the EBS is F=ma, where F is the braking force, a is the deceleration, F can be equivalently converted into the wheel-side braking force when the brake pressure is known, and a is the deceleration value calculated by the wheel-side speed, so the vehicle mass m=F / a.

[0092] In another embodiment of the present invention, when determining the vehicle load state, the VCU also uses F=ma for calculation. At this time, F is the driving force, a is the acceleration, and F can be used to calculate the driving force of the entire vehicle based on the motor torque signal and the gear signal. a is the acceleration calculated through the front axle speed feedback from the EBS. Therefore, the vehicle mass m=F / a.

[0093] Specifically, when the vehicle is powered on, it is static, so F and a are not available for the time being. At this time, the vehicle mass m is initially set according to the default value of half load. When the vehicle starts running and there is an acceleration or deceleration process, the vehicle mass m will be iteratively updated, and the real-time calculated value will be weighted with the historical value, such as m0+m1+m2+…+mx / t=average m. During the iteration process, the m value will become more and more accurate as the vehicle runs.

[0094] In one embodiment of the present invention, after obtaining the vehicle mass signal, the vehicle mass received by the VCU is compared with a preset load threshold, and based on the comparison result, the current load state of the vehicle is classified into corresponding levels, such as no load, light load, medium load or full load.

[0095] In one embodiment of the present invention, the driving mode can be directly switched according to the current load state of the vehicle. For example, when it is confirmed that the current load state is no-load or light-load, it is determined to switch to the single-bridge driving mode, and the small-power bridge is selected as the main driving axle; when it is confirmed that the current load state is medium-load, it is determined to switch to the single-bridge driving mode, and the high-power bridge is selected as the main driving axle; when it is confirmed that the current load state is heavy-load, the high-power bridge is maintained as the main driving axle, or the dual-bridge driving mode is switched.

[0096] In one embodiment of the present invention, the driving mode can also be judged and switched according to the specific value of the vehicle mass, including the following steps S131 to S134:

[0097] Step S131, setting the mass coefficient, mapping the vehicle mass range to a preset mass coefficient range, such as setting the mass coefficient within the vehicle mass range of 10000kg to 100000kg to 10, where 10000kg corresponds to a mass coefficient of 1, 15000kg corresponds to a mass coefficient of 1.5, 20000kg corresponds to a mass coefficient of 2, and so on. The mass coefficient is not necessarily an integer, and it can be considered as a normalized representation of the vehicle mass or a linear scaling value.

[0098] Step S132, when the quality coefficient is less than the first preset threshold, it is determined to switch to the single-bridge drive mode, and the small-power bridge is selected as the main drive bridge. Specifically, the first preset threshold can be configured as 2.5. When the quality coefficient is less than 2.5, it can be determined that the small-power bridge can meet most working conditions, so it is set as the main drive bridge.

[0099] Step S133, when the quality coefficient is greater than the second preset threshold and less than the third preset threshold, it is determined to switch to the single-bridge drive mode, and the high-power bridge is selected as the main drive bridge. Specifically, the second preset threshold can be configured to 4. When the quality coefficient is greater than 4, it can be determined that the high-power bridge can meet most working conditions, so it is set as the main drive bridge.

[0100] Step S134, when the quality coefficient is greater than or equal to the third preset threshold, the dual-bridge driving mode is maintained. Specifically, the third preset threshold can be configured as 6. When the quality coefficient is greater than 6, the high-power bridge can no longer be maintained within the rated range, so the dual-bridge driving mode is adopted.

[0101] In one embodiment of the present invention, the road slope angle is determined based on the vehicle operating parameters; the calculated slope angle is compared with a preset flat ground threshold and a ramp threshold, and the current road condition is determined based on the comparison result.

[0102] Specifically, the road slope angle can be calculated based on the vehicle acceleration and angular velocity obtained by the inertial measurement unit (IMU), or the slope can be estimated by monitoring the engine torque, power output, accelerator pedal position and other data combined with the vehicle's dynamic model. The specific slope calculation method can adopt any implementation method disclosed in the prior art, and is not specifically limited in this embodiment.

[0103] In one embodiment of the present invention, the flat ground threshold may be set to 1.5%, and the slope threshold may be set to 6%.

[0104] In one embodiment of the present invention, when it is determined that the current road condition is uphill and the slope angle is greater than a preset slope threshold, regardless of the mass coefficient, the dual-axle drive mode is maintained or switched to reduce the risk of single-axle overload, thereby providing a greater total driving force to overcome gravity and slope resistance.

[0105] In one embodiment of the present invention, when the road slope angle is between the flat ground threshold and the slope threshold, it can be determined whether the driving mode needs to be adjusted based on other factors (such as vehicle speed, load, etc.), and technical personnel in this field can make specific settings based on specific vehicle models and usage scenarios.

[0106] Step S140, determining the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operating intention, and triggering switching to the dual-axle drive mode when they exceed respective preset thresholds.

[0107] In one embodiment of the present invention, step S140 also includes steps S1411 to S1414, and steps S1421 to S1425. It should be noted that steps S1411 to S1414 and steps S1421 to S1425 are not performed simultaneously.

[0108] Step S1411, obtain the current transmission gear information and real-time accelerator pedal opening signal. The transmission gear information is obtained through the vehicle's transmission control unit TCU, and the accelerator pedal opening signal is obtained through the pedal position sensor, which can be expressed in the range of 0-100%, 0% means no pedal, and 100% means full pedal.

[0109] Step S1412, according to the current gear, determine the corresponding maximum driving force boundary value; specifically, the maximum driving force boundary value changes with the current gear, the low gear corresponds to a greater driving force, and the high gear corresponds to a smaller driving force but a higher speed. The determination of the specific boundary value depends on the vehicle's power characteristic curve, the output characteristics of the motor, the transmission ratio of the gearbox and other parameters, which are not specifically limited in this embodiment.

[0110] Step S1413, compare the real-time accelerator pedal opening signal with the maximum driving force boundary value corresponding to the current gear. First, map the pedal opening to the driving force range of the current gear, continuously monitor the pedal opening signal, and convert it into the corresponding driving force requirement in real time, and then compare this requirement with the maximum driving force boundary value of the current gear.

[0111] Step S1414: when the accelerator pedal opening signal exceeds a preset percentage of the maximum driving force boundary value, switching to the dual-bridge driving mode is triggered.

[0112] In one embodiment of the present invention, the preset percentage can be set in the range of 80-90%. For example, if it is set to 85%, when the driving force demand corresponding to the pedal opening exceeds 85% of the maximum driving force, it indicates that the driver needs a greater power output. At this time, the dual-axle drive mode is immediately triggered to switch, and the other drive axle is activated to provide optimal performance.

[0113] S1421, setting multiple levels of braking energy recovery intensity, each level corresponds to a different braking force; specifically, the braking energy recovery intensity can be set according to the number of braking energy recovery gears, and the higher the level, the higher the energy recovery efficiency.

[0114] S1422, obtaining the braking energy recovery gear signal selected by the driver.

[0115] S1423, compare the selected braking energy recovery gear signal with the preset braking energy recovery intensity; when comparing, first map each braking energy recovery gear to the braking force range of the current gear, and then compare it with the braking energy recovery intensity of the corresponding level.

[0116] S1424, when the selected braking energy recovery gear signal is greater than or equal to the braking energy recovery intensity, trigger switching to the dual-bridge drive mode to provide a stronger braking effect.

[0117] S1425, monitor the vehicle speed, and when the vehicle speed drops to a preset low-speed threshold, re-evaluate whether it is necessary to maintain the dual-axle drive mode.

[0118] In one embodiment of the present invention, the low-speed threshold can be set to 20 km / h. When the speed drops below the threshold, it is re-determined whether the dual-bridge mode is needed. The judgment conditions can be set based on factors such as remaining kinetic energy, battery status, road conditions, etc. If high-intensity energy recovery is no longer needed, it can be switched back to single-bridge mode. If it is still needed, the dual-bridge mode is maintained.

[0119] In one embodiment of the present invention, it also includes fault diagnosis and processing steps, specifically including steps S1431 to S1434.

[0120] Step S1431, based on the vehicle operating parameters, real-time monitoring of the vehicle's operating status.

[0121] Step S1432, when a fault is detected, specific fault information is identified through a preset fault code, and the code may include system identification, fault type, severity and other information.

[0122] Step S1433, determine the type and severity of the fault based on the identified fault information, where the fault type can indicate the location of the fault and the specific cause of the fault, such as indicating a motor fault, and further determine whether it is overcurrent, overheating or short circuit; the severity type can include mild, moderate and severe.

[0123] Step S1434, based on the fault type and severity, execute the corresponding single-double bridge switching strategy, which specifically includes: when the motor controller, motor or gearbox of a single drive axle fails seriously and cannot be used, quickly disconnect the power supply of the faulty bridge, and immediately activate and switch to the other drive axle as the drive to ensure that the power is not interrupted and the available power output is maximized while ensuring safety; when a torque limit fault is detected, gradually limit the torque output of the faulty bridge, and steadily increase the torque distribution ratio of the other drive axle; when switching the drive mode under fault conditions, dynamically transfer the drive torque based on the torque adjustment strategy to ensure a smooth transition of the total driving force and avoid sudden power changes; continuously monitor the fault status, and when the fault is resolved, do not immediately restore the original state, but re-evaluate the drive mode and gradually restore the original function to ensure safety.

[0124] Step S150: determining the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched.

[0125] In one embodiment of the present invention, the required total driving torque is first calculated according to the current driving conditions, and then the target torque is allocated according to the switched driving mode. For the single-bridge mode, the target torque is the total required torque; for the dual-bridge mode, the target torque needs to be allocated according to the power characteristics and current status of the two drive axles.

[0126] In one embodiment of the present invention, the torque adjustment strategy is the torque transfer rate, which is a calibrated value, indicating the amount of torque transferred from one drive axle to another drive axle per unit time, and determines the speed and smoothness of the drive mode switching. When switching from a single-axle drive mode to a dual-axle drive mode, the transfer rate is determined based on the torque transfer deviation. A larger deviation may correspond to a faster transfer rate, while a smaller deviation corresponds to a slower rate. Specifically, a table lookup method or an interpolation algorithm may be used to determine the specific transfer rate.

[0127] Step S160 , during the switching process of the driving mode, based on the torque adjustment strategy, dynamically adjust the driving torque so that it gradually converges to the target driving torque.

[0128] In one embodiment of the present invention, after the driving mode is determined, the output torque of each drive axle is gradually adjusted according to a predetermined time curve. For switching from a single axle to a dual axle, the torque of the original drive axle is gradually reduced, while the torque of the newly activated drive axle is increased; for switching from a dual axle to a single axle, the torque of the remaining drive axle is gradually increased, while the torque of the drive axle to be deactivated is reduced. As the adjustment process proceeds, the gap between the actual torque and the target torque is continuously reduced.

[0129] Compared with the prior art, the control method provided by the above embodiment can improve the driving performance and energy utilization efficiency of the vehicle, and focuses on optimizing the energy consumption performance of dual-electric drive axle tractors with different powers to provide the best driving state, so that the vehicle can obtain the best driving force under different conditions, and improve the vehicle's acceleration performance, climbing ability, etc. Under the premise of meeting the dynamic requirements, the motor system, transmission system, etc. are all working in the best state, thereby reducing energy consumption and extending the vehicle's cruising range; in addition, this control method can timely discover and solve problems by real-time monitoring of the system's operating status and performing fault diagnosis and processing, ensuring the safe and reliable operation of the system.

[0130] like Figure 2 In an embodiment of the present invention, a single-double bridge switching control system for dual-drive bridges with different powers is also provided, and the system at least includes:

[0131] The initial driving module 210 is used to initialize the dual-bridge driving mode after starting.

[0132] The acquisition module 220 is used to acquire vehicle operating parameters and driver operation intentions, and perform a re-evaluation of the driving mode.

[0133] The first evaluation module 230 is used to determine the current road condition and / or vehicle load according to the vehicle operating parameters, at least based on the current road condition or vehicle load, determine whether to switch to the single-bridge drive mode, and determine the main driving axle in the single-bridge drive mode.

[0134] The second evaluation module 240 is used to determine the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operating intention, and trigger switching to the dual-axle drive mode when they exceed respective preset thresholds.

[0135] The torque control module 250 is used to determine the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched.

[0136] The driving mode switching module 260 is used to dynamically adjust the driving torque based on the torque adjustment strategy during the switching process of the driving mode, so that the driving torque gradually converges to the target driving torque.

[0137] In one embodiment of the present invention, the system further includes a fault diagnosis processing module 270 for real-time monitoring of the vehicle's operating status, determining whether a fault exists, and executing a corresponding single-bridge or double-bridge switching strategy based on the type and severity of the fault.

[0138] It should be noted that the single-double bridge switching control system for dual-drive axles of different powers provided in the above-mentioned embodiments and the embodiments of the single-double bridge switching control method for dual-drive axles of different powers belong to the same concept. The specific implementation process is detailed in the embodiments of the control method, which will not be repeated here one by one.

[0139] An embodiment of the present invention further provides a pure electric commercial vehicle, which is equipped with the above-mentioned single-double-bridge switching control system for dual-drive axles of different powers, or the vehicle can implement the above-mentioned single-double-bridge switching control method for dual-drive axles of different powers.

[0140] An embodiment of the present invention further provides an electronic device, which includes a memory and a processor, wherein a computer program executed by the processor is stored in the memory, and when the computer program is executed by the processor, the processor executes the single-double bridge switching control method of the double-drive bridge with different powers in the foregoing text. Various applications and various data, such as various data used and / or generated by the application, can also be stored in the memory. The processor can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other forms of processing units with data processing capabilities and / or instruction execution capabilities.

[0141] The embodiment of the present invention also provides a computer-readable storage medium, on which a computer program executed by a processor is stored. When the computer program is executed by the processor, the processor executes the single-double bridge switching control method of the dual-drive bridge with different powers as described above. Exemplarily, the computer storage medium may include a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0142] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0143] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0144] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0145] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0146] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A single-bridge and double-bridge switching control method for dual-drive bridges with different powers, characterized in that: The method comprises: Initialize the dual-bridge drive mode after starting; Obtain vehicle operating parameters and driver operation intentions to re-evaluate the driving mode; determining a current road condition and / or a vehicle load according to vehicle operating parameters, determining whether to switch to a single-axle drive mode based at least on the current road condition or the vehicle load, and determining a main driving axle in the single-axle drive mode; Determine the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operating intention, and trigger switching to the dual-axle drive mode when the respective preset thresholds are exceeded; Determine the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched; During the switching process of the driving mode, the driving torque is dynamically adjusted based on the torque adjustment strategy so that it gradually converges to the target driving torque.

2. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1 is characterized in that: The step of initializing the dual-bridge driving mode after starting specifically includes: Determine whether the vehicle is in the starting state; When the vehicle is confirmed to be in the starting state, two drive axles with different powers are activated at the same time, and the initial drive torque of the two drive axles is dynamically distributed; The vehicle speed is monitored and when the vehicle speed reaches a preset speed threshold, a re-evaluation of the driving mode is triggered.

3. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1, characterized in that: The step of obtaining the vehicle operating parameters and the driver's operating intention specifically includes: Acquire vehicle operating parameters, wherein the vehicle operating parameters include at least one of vehicle speed, acceleration, motor temperature, current gear position of the gearbox, motor allowable torque, motor allowable current, battery remaining power, battery allowable current, and load signal; The driver's operation intention is obtained, where the driver's operation intention includes at least one of a driving mode selection, an accelerator pedal opening, a brake pedal opening, an RND gear request, and an energy recovery gear signal.

4. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 3 is characterized in that: The step of determining the current road condition or vehicle load according to the vehicle operating parameters specifically includes: Obtaining the driving force and acceleration of the vehicle, or obtaining the braking force and deceleration of the vehicle; Determining the current vehicle mass based on a relationship between driving force and acceleration, or based on a relationship between braking force and deceleration; Compare the obtained vehicle mass with the preset unloaded mass and fully loaded mass; Based on the comparison result, the vehicle load state is determined.

5. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 4, characterized in that: The step of determining the current road condition or vehicle load according to the vehicle operating parameters specifically includes: Determining a road slope angle based on vehicle operating parameters; The calculated slope angle is compared with the preset flat ground threshold and ramp threshold, and the current road condition is determined based on the comparison result.

6. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1, characterized in that: The step of judging whether to switch to the single-bridge drive mode at least based on the current road condition or vehicle load, and determining the main driving axle in the single-bridge drive mode specifically includes: Set the mass coefficient to map the vehicle mass range to the preset mass coefficient range; When the mass coefficient is less than the first preset threshold, it is determined to switch to the single-bridge drive mode, and the low-power bridge is selected as the main drive bridge; When the mass coefficient is greater than the second preset threshold and less than the third preset threshold, it is determined to switch to the single-bridge drive mode and select the high-power bridge as the main drive bridge; When the quality coefficient is greater than or equal to the third preset threshold, the dual-bridge driving mode is maintained.

7. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 6 is characterized in that: The step of determining whether to switch to the single-bridge drive mode based at least on the current road condition or vehicle load, and determining the main driving axle in the single-bridge drive mode, further includes: When it is determined that the current road condition is uphill and the slope angle is greater than the preset slope threshold, regardless of the mass coefficient, the dual-axle drive mode is maintained or switched to.

8. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1, characterized in that: The step of determining the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention, and triggering switching to the dual-axle drive mode when the respective preset thresholds are exceeded, specifically includes: Obtain current gearbox gear information and real-time accelerator pedal opening signal; According to the current gear position, determine the corresponding maximum driving force boundary value; Compare the real-time accelerator pedal opening signal with the maximum driving force boundary value corresponding to the current gear position; When the accelerator pedal opening signal exceeds a preset percentage of the maximum driving force boundary value, switching to the dual-axle driving mode is triggered.

9. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1, characterized in that: The step of determining the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention, and triggering switching to the dual-axle drive mode when the respective preset thresholds are exceeded, specifically includes: Set multiple levels of braking energy recovery intensity, each level corresponds to different braking force; Obtaining a brake energy recovery gear position signal selected by a driver; comparing the selected braking energy recovery gear signal with a preset braking energy recovery intensity; When the selected braking energy recovery gear signal is greater than or equal to the braking energy recovery intensity, switching to the dual-axle drive mode is triggered; The vehicle speed is monitored and when the vehicle speed drops to a preset low-speed threshold, the system re-evaluates whether it is necessary to maintain the dual-axle drive mode.

10. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 1, characterized in that: The method also includes the steps of fault diagnosis and processing: Based on vehicle operating parameters, real-time monitoring of vehicle operating status; When a fault is detected, the specific fault information is identified through the preset fault code; Determine the type and severity of the fault based on the identified fault information; Based on the fault type and severity, the corresponding single-bridge or double-bridge switching strategy is executed.

11. The single-bridge and double-bridge switching control method of dual-drive bridges with different powers according to claim 10, characterized in that: The step of executing the corresponding single-bridge and double-bridge switching strategy based on the fault type and severity specifically includes: When the motor controller, motor or gearbox of a single drive axle fails seriously and cannot be used, it will automatically switch to another drive axle as the drive; When a torque limit fault is detected, the torque output of the faulty axle is limited and the torque distribution ratio of the other drive axle is increased; When switching drive modes in the event of a fault, the drive torque is dynamically transferred based on the torque adjustment strategy; The fault condition is continuously monitored and the drive mode is re-evaluated when the fault condition is resolved.

12. A single-bridge and double-bridge switching control system for dual-drive bridges with different powers, characterized in that: The system comprises: Initial drive module, used to initialize the dual-bridge drive mode after starting; An acquisition module, used to acquire vehicle operating parameters and driver operation intentions, and perform a re-evaluation of the driving mode; A first evaluation module, configured to determine a current road condition and / or a vehicle load according to a vehicle operating parameter, determine whether to switch to a single-axle drive mode at least based on the current road condition or the vehicle load, and determine a main driving axle in the single-axle drive mode; The second evaluation module is used to determine the accelerator pedal opening and / or the brake energy recovery gear according to the driver's operation intention, and trigger the switch to the dual-axle drive mode when the respective preset thresholds are exceeded; A torque control module, used to determine the target driving torque and torque adjustment strategy required by the drive axle based on the driving mode to be switched; The driving mode switching module is used to dynamically adjust the driving torque based on the torque adjustment strategy during the switching process of the driving mode so that it gradually converges to the target driving torque.

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